Surface-emitting laser measuring method, manufacturing method, measuring apparatus, and non-transitory computer-readable medium

ABSTRACT

A surface-emitting laser measuring method includes the steps of causing at least one surface-emitting laser to emit light; and measuring a light intensity and a spectrum of the at least one surface-emitting laser by splitting the light emitted from the at least one surface-emitting laser in the step of causing the at least one surface-emitting laser to emit light and causing one split beam to be incident on a light-intensity measuring unit while causing another split beam to be incident on a spectrum measuring unit.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present disclosure relates to surface-emitting laser measuringmethods, manufacturing methods, measuring apparatuses, andnon-transitory computer-readable mediums.

This application is based on and claims priority to Japanese PatentApplication No. 2020-147379 filed on Sep. 2, 2020, and the entirecontents of the Japanese patent application are incorporated herein byreference.

2. Description of the Related Art

In a process of manufacturing surface-emitting lasers (vertical-cavitysurface-emitting lasers (VCSELs)), a plurality of surface-emittinglasers arranged in an array are caused to emit light for characteristicinspection. There is a technique in which electrical signals withdifferent frequencies are input to a plurality of surface-emittinglasers, and the emitted light is analyzed for each frequency to measurethe light intensity (e.g., Japanese Unexamined Patent ApplicationPublication No. 2010-16110).

SUMMARY OF THE INVENTION

In addition to the light intensity of surface-emitting lasers, the lightspectrum may be measured. However, it takes time to sequentially measurethe light intensity and the spectrum. Accordingly, an object of thepresent disclosure is to provide a surface-emitting laser measuringmethod, manufacturing method, measuring apparatus, and measuring programthat allow for a shortened measurement time.

A surface-emitting laser measuring method according to one aspect of thepresent disclosure includes the steps of causing at least onesurface-emitting laser to emit light; and measuring a light intensityand a spectrum of the at least one surface-emitting laser by splittingthe light emitted from the at least one surface-emitting laser in thestep of causing the at least one surface-emitting laser to emit lightand causing one split beam to be incident on a light-intensity measuringunit while causing another split beam to be incident on a spectrummeasuring unit.

A surface-emitting laser manufacturing method according to anotheraspect of the present disclosure includes the steps of forming aplurality of surface-emitting lasers on a wafer; and subjecting theplurality of surface-emitting lasers to the measuring method describedabove.

A surface-emitting laser measuring apparatus according to another aspectof the present disclosure includes a light-emission causing unitconfigured to cause at least one surface-emitting laser to emit light; asplitting unit configured to split the light emitted from the at leastone surface-emitting laser; a light-intensity measuring unit configuredto measure a light intensity of the at least one surface-emitting laserby receiving one split beam from the splitting unit; and a spectrummeasuring unit configured to measure a spectrum of the at least onesurface-emitting laser by receiving another split beam.

A non-transitory computer-readable medium according to an embodiment ofthe present disclosure has stored therein a program for causing acomputer to execute a process. The process includes the steps of causingat least one surface-emitting laser to emit light; and measuring a lightintensity and a spectrum of the at least one surface-emitting laserusing the light emitted from the at least one surface-emitting laser inthe step of causing the at least one surface-emitting laser to emitlight, the light being split and incident on a light-intensity measuringunit and a spectrum measuring unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic view illustrating an example measuring apparatusaccording to one embodiment.

FIG. 1B is a block diagram illustrating the hardware configuration of acontrol unit.

FIG. 2 is a plan view illustrating an example wafer.

FIG. 3 is a flowchart illustrating an example surface-emitting lasermanufacturing method.

FIG. 4 is a flowchart illustrating an example characteristic measuringmethod.

FIG. 5A is a schematic view illustrating an example measuring apparatusaccording to a comparative example.

FIG. 5B is a schematic view illustrating the example measuring apparatusaccording to the comparative example.

FIG. 6 is a flowchart illustrating an example measuring method in thecomparative example.

FIG. 7 is a flowchart illustrating the example measuring method in thecomparative example.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Description of Embodiments ofthe Disclosure

First, embodiments of the present disclosure will be listed anddescribed.

(1) One embodiment of the present disclosure is a surface-emitting lasermeasuring method including the steps of causing at least onesurface-emitting laser to emit light; and measuring a light intensityand a spectrum of the at least one surface-emitting laser by splittingthe light emitted from the at least one surface-emitting laser in thestep of causing the at least one surface-emitting laser to emit lightand causing one split beam to be incident on a light-intensity measuringunit while causing another split beam to be incident on a spectrummeasuring unit. Because the light intensity and the spectrum aresimultaneously measured, the measurement time can be shortened.

(2) The at least one surface-emitting laser may include a plurality ofsurface-emitting lasers arranged on a wafer, the plurality ofsurface-emitting lasers including a first surface-emitting laser and asecond surface-emitting laser. After the first surface-emitting laser issubjected to the step of causing light emission and the step ofmeasuring the light intensity and the spectrum, the secondsurface-emitting laser may be subjected to the step of causing lightemission and the step of measuring the light intensity and the spectrum.Because the light intensity and spectrum of a plurality ofsurface-emitting lasers are simultaneously measured, the measurementtime can be further shortened.

(3) The surface-emitting laser measuring method may further include thesteps of positioning a splitting unit configured to split the light overthe first surface-emitting laser; and after the step of measuring thelight intensity and the spectrum of the first surface-emitting laser,positioning the splitting unit over the second surface-emitting laser.The step of measuring the light intensity and the spectrum may includemeasuring the light intensity and the spectrum by causing one split beamfrom the splitting unit to be incident on the light-intensity measuringunit while causing another split beam to be incident on the spectrummeasuring unit. The time for alignment of the splitting unit and thesurface-emitting lasers can be shortened.

(4) The step of causing the at least one surface-emitting laser to emitlight may include changing an amplitude of electrical signals input tothe at least one surface-emitting laser to cause the at least onesurface-emitting laser to emit light for each of the electrical signalswith different amplitudes, and the step of measuring the light intensityand the spectrum of the at least one surface-emitting laser may includemeasuring the light intensity and the spectrum when the amplitude of theelectrical signals reaches a predetermined level. Characteristicevaluation in cases where electrical signals are changed can beperformed within a short period of time.

(5) Another embodiment of the present disclosure is a surface-emittinglaser manufacturing method including the steps of forming a plurality ofsurface-emitting lasers on a wafer; and subjecting the plurality ofsurface-emitting lasers to the measuring method described above. Themeasurement time for the surface-emitting lasers can be shortened duringthe manufacturing process.

(6) Another embodiment of the present disclosure is a surface-emittinglaser measuring apparatus including a light-emission causing unitconfigured to cause at least one surface-emitting laser to emit light; asplitting unit configured to split the light emitted from the at leastone surface-emitting laser; a light-intensity measuring unit configuredto measure a light intensity of the at least one surface-emitting laserby receiving one split beam from the splitting unit; and a spectrummeasuring unit configured to measure a spectrum of the at least onesurface-emitting laser by receiving another split beam. Because thelight intensity and the spectrum are simultaneously measured, themeasurement time can be shortened.

(7) The splitting unit may be configured to split light at an emissionwavelength of the at least one surface-emitting laser in a predeterminedproportion. The light intensity and the spectrum can be accuratelyacquired based on the split proportion and the measurement results ofthe light intensity.

(8) The at least one surface-emitting laser may include a plurality ofsurface-emitting lasers arranged on a wafer, and the surface-emittinglaser measuring apparatus may further include a temperature control unitconfigured to control a temperature of the wafer. Because thetemperature control unit controls the temperature and the measurementtime is shortened, less temperature change occurs. The change in thecharacteristics of the surface-emitting lasers with temperature changecan be reduced.

(9) Another embodiment of the present disclosure is a non-transitorycomputer-readable medium having stored therein a program for causing acomputer to execute a process, the process including the steps ofcausing at least one surface-emitting laser to emit light; and measuringa light intensity and a spectrum of the at least one surface-emittinglaser using the light emitted from the at least one surface-emittinglaser in the step of causing the at least one surface-emitting laser toemit light, the light being split and incident on a light-intensitymeasuring unit and a spectrum measuring unit. Because the lightintensity and the spectrum are simultaneously measured, the measurementtime can be shortened.

Details of Embodiments of the Disclosure

A specific example of a surface-emitting laser measuring method,manufacturing method, measuring apparatus, and measuring programaccording to one embodiment of the present disclosure will hereinafterbe described with reference to the drawings. It should be understood,however, that the disclosure is not limited to the illustrated example,but is indicated by the claims, and all changes that come within themeaning and range of equivalency of the claims are intended to beembraced therein.

Measuring Apparatus

FIG. 1A is a schematic view illustrating an example measuring apparatus100 according to one embodiment. As illustrated in FIG. 1A, themeasuring apparatus 100 includes a control unit 10, a current/voltagesource 20 (light-emission causing unit), a stage 22, a thermochuck 24(temperature control unit), a pair of probes 26, lenses 28, 31, and 36,a beam splitter 30 (splitting unit), a photodetector 32, a power meter34, and a spectrometer 38 (spectrum measuring unit). The X-axisdirection, the Y-axis direction, and the Z-axis direction are orthogonalto each other.

The main surfaces of the stage 22, the thermochuck 24, and a wafer 50are located in the XY-plane. The direction normal to these main surfacesis the Z-axis direction. The thermochuck 24 is mounted on the stage 22,and the wafer 50 is mounted on the thermochuck 24. The stage 22 ismovable to change the position in the XY-plane and the height in theZ-axis direction of the thermochuck 24 and the wafer 50. The thermochuck24 is a stage capable of temperature control and holds the wafer 50 bysuction.

FIG. 2 is a plan view illustrating an example wafer 50. A plurality ofsurface-emitting lasers 52 are arranged in a two-dimensional grid on thewafer 50. For example, a 3 inch wafer 50 has 40,000 surface-emittinglasers 52. The surface-emitting lasers 52 are formed of, for example,compound semiconductors, and include a lower cladding layer, a corelayer, and an upper cladding layer stacked together on the wafer 50. Thewafer 50 is, for example, a semiconductor substrate formed of galliumarsenide (GaAs). The lower cladding layer and the upper cladding layerare formed of, for example, aluminum gallium arsenide (AlGaAs). The corelayer is formed of, for example, indium gallium arsenide (InGaAs), andhas a multi-quantum well (MQW) structure. When an electrical signal(current) is input to the surface-emitting lasers 52, they emit lightwith a wavelength of, for example, 800 nm to 1,000 nm in the Z-axisdirection.

The current/voltage source 20 illustrated in FIG. 1A has a pair ofprobes 26 corresponding to n- and p-electrodes of the surface-emittinglasers 52. The probes 26 are formed of, for example, a metal, and isbrought into contrast with pads (not illustrated) of thesurface-emitting lasers 52. The current/voltage source 20 inputs anelectrical signal (current) to the surface-emitting lasers 52 on thewafer 50 through the probes 26 to cause the surface-emitting lasers 52to emit light. The current from the current/voltage source 20 can bechanged. The current is changed stepwise, for example, in steps of 0.2mA or 0.5 mA within the range of 0 to 10 mA.

The wafer 50, the lens 28, the beam splitter 30, the lens 31, and thephotodetector 32 are arranged in sequence in the Z-axis direction. Thebeam splitter 30, the lens 36, and the spectrometer 38 are arranged insequence in the X-axis direction.

The lens 28 is an objective lens. The lenses 31 and 36 are condenserlenses. The beam splitter 30 is, for example, a cube with a side lengthof 25 mm to 50 mm, and splits light in the Z-axis direction and theX-axis direction. The proportion in which the beam splitter 30 splitslight is determined by the wavelength of the light. For example, thebeam splitter 30 splits light at the emission wavelength of thesurface-emitting lasers 52 in a proportion of 1:1. The photodetector 32and the power meter 34 function as a light-intensity measuring unit. Thephotodetector 32 includes, for example, a photodiode or an integratingsphere, and receives light to output an electrical signal. The powermeter 34 is electrically connected to the photodetector 32 anddetermines the light intensity based on the electrical signal input fromthe photodetector 32. The lens 36 is coupled to the spectrometer 38, forexample, with an optical fiber. The spectrometer 38 measures thespectrum of the input light.

Light emitted from the surface-emitting lasers 52 on the wafer 50propagates through the lens 28 into the beam splitter 3, which splitsthe light. One split beam propagates from the beam splitter 30 in theZ-axis direction and is focused onto the photodetector 32 by the lens31. The other beam propagates from the beam splitter 30 in the X-axisdirection and is focused onto the spectrometer 38 by the lens 36.Because the light is split, the light intensity and the spectrum can besimultaneously measured.

The control unit 10 is, for example, a control device such as a personalcomputer, and is electrically connected to the current/voltage source20, the stage 22, the power meter 34, and the spectrometer 38.

FIG. 1B is a block diagram illustrating the hardware configuration ofthe control unit 10. As illustrated in FIG. 1B, the control unit 10includes a central processing unit (CPU) 40, a random-access memory(RAM) 42, a storage device 44, and an interface 46. The CPU 40, the RAM42, the storage device 44, and the interface 46 are connected to eachother, for example, via a bus. The RAM 42 is a volatile memory fortemporarily storing, for example, programs and data. The storage device44 is, for example, a read-only memory (ROM), a solid-state drive (SSD)such as a flash memory, or a hard disc drive (HDD). The storage device44 stores, for example, a measuring program described later.

The CPU 40 executes the programs stored in the RAM 42 to implementvarious sections in the control unit 10, such as an electrical signalcontrol section 12, a position control section 14, a power meter controlsection 16, and a spectrometer control section 18 in FIG. 1A. Thevarious sections of the control unit 10 may also be implemented byhardware such as circuitry. The electrical signal control section 12controls the current/voltage source 20, for example, to switch on andoff the current input to the wafer 50 and change the current. Theposition control section 14 controls the stage 22 to adjust the positionof the wafer 50. The power meter control section 16 controls the powermeter 34 to acquire the light intensity from the power meter 34. Thespectrometer control section 18 controls the spectrometer 38 to acquirethe spectrum from the spectrometer 38.

Manufacturing Method and Measuring Method

FIG. 3 is a flowchart illustrating an example surface-emitting lasermanufacturing method. As illustrated in FIG. 3, a plurality ofsurface-emitting lasers 52 are formed on the wafer 50 (step Si).Specifically, for example, a lower cladding layer, a core layer, and anupper cladding layer are epitaxially grown on the wafer 50 by metalorganic chemical vapor deposition (MOCVD). A mesa serving as a lightemitting portion is formed, for example, by etching. Electrodes areformed, for example, by resist patterning and evaporation. After thesurface-emitting lasers 52 are formed, the characteristics of thesurface-emitting lasers 52 are evaluated (step S2, FIG. 4). After theevaluation, the wafer 50 is diced (step S3).

The characteristic evaluation will now be described in detail. FIG. 4 isa flowchart illustrating an example characteristic measuring method,which is performed in step S2 in FIG. 3. One of the surface-emittinglasers 52 on the wafer 50 is aligned to the lens 28 and the beamsplitter 30 in advance. The distance between the lens 28 and thesurface-emitting laser 52 is, for example, 5 cm. As illustrated in FIG.4, the current/voltage source 20 causes the probes 26 to be moved intocontact with the electrodes of the surface-emitting laser 52 (step S10).The current/voltage source 20 supplies a current through the probes 26to the surface-emitting laser 52, thereby inputting an electrical signal(current) (step S12). As the current is input, the surface-emittinglaser 52 emits light. As illustrated in FIG. 1A, the beam splitter 30splits the light in the X-axis direction and the Z-axis direction. Thesplit beams are incident on the photodetector 32 and the spectrometer38.

The control unit 10 determines whether the current I input to thesurface-emitting laser 52 is equal to a predetermined current Is (stepS14). If no, the spectrometer control section 18 blocks a trigger fromthe current/voltage source 20 to the spectrometer 38. No trigger isinput to the spectrometer 38, and no spectrum measurement is performed.The photodetector 32 and the power meter 34 measure the light intensity(step S20). The electrical signal control section 12 determines whetherall steps of the current are complete (step S22). If no, the electricalsignal control section 12 changes the current, for example, by 0.2 mA(step S24). Thereafter, step S14 is performed again. The electricalsignal control section 12 changes the current stepwise, for example, insteps of 0.2 mA within the range of 0 to 10 mA.

If the current I is equal to the predetermined current Is (yes in stepS14), the current/voltage source 20 transmits a trigger, and thespectrometer control section 18 does not block the trigger (step S16).In response to the trigger, the spectrometer 38 measures the spectrum(step S18). Concurrently with the spectrum measurement, thephotodetector 32 and the power meter 34 measure the light intensity(step S20).

If the control unit 10 determines that all steps of the current, forexample, within the range of 0 to 10 mA, are complete (yes in step S22),the current/voltage source 20 causes the probes 26 to be moved away fromthe surface-emitting laser 52 (step S26). The control unit 10 determineswhether the measurement on the surface-emitting lasers 52 designated formeasurement (designated chips) on the wafer 50 is complete (step S28).For example, all of the plurality of surface-emitting lasers 52 on thewafer 50, half of the chips, 60% of the chips, or 80% of the chips maybe designated for measurement.

If no, the stage 22 moves the wafer 50 to position the next chip(surface-emitting laser 52) under the lens 28 and the beam splitter 30(step S29). Step S10 and the subsequent steps are performed on thatchip. The measurement ends when the measurement on the surface-emittinglasers 52 designated for measurement on the wafer 50 is complete (yes instep S28).

As illustrated in FIG. 3, dicing is performed after the characteristicmeasurement (step S3). Chips including a single surface-emitting laser52 or array chips including a plurality of surface-emitting lasers 52may be formed.

FIGS. 5A and 5B are schematic views illustrating an example measuringapparatus 110 according to a comparative example. The measuringapparatus 110 does not include the beam splitter 30. In the example inFIG. 5A, the lens 31 and the photodetector 32 are positioned over thewafer 50 so that the photodetector 32 can receive light. Thespectrometer 38 does not receive light because the lens 36 is notaligned to the wafer 50. In the example in FIG. 5B, the lens 36 ispositioned over the wafer 50 so that the spectrometer 38 receives light.The photodetector 32 is not aligned to the wafer 50 and therefore doesnot receive light.

FIGS. 6 and 7 are flowcharts illustrating an example measuring method inthe comparative example. Step S30 in FIG. 6 and step S48 in FIG. 7 areidentical to step S10 in FIG. 4. Steps S32 and S50 are identical to stepS12. Steps S36 and S54 are identical to step S22. Steps S38 and S56 areidentical to step S24. Steps S40 and S58 identical to step S26. StepsS42 and S60 are identical to step S28. Steps S44 and S62 are identicalto step S29. Step S34 in FIG. 6 is identical to step S20, i.e., a lightintensity measurement step. Step S52 in FIG. 7 is identical to step S18,i.e., a spectrum measurement step.

In the steps in FIG. 6, as illustrated in FIG. 5A, the lens 31 and thephotodetector 32 are positioned over the wafer 50. In steps S30 to S42in FIG. 6, a current is input to the designated chips on the wafer 50,and the light intensity of the surface-emitting lasers 52 is measured.Thereafter, switching is made from the configuration in FIG. 5A to theconfiguration in FIG. 5B so that the lens 36 and the spectrometer 38 arepositioned over the wafer 50 (step S46). In steps S48 to S60 in FIG. 7,a current is input to the designated chips on the wafer 50, and thespectrum of the surface-emitting lasers 52 is measured.

As illustrated in FIGS. 6 and 7, the light intensity and the spectrumare measured in different processes in the comparative example. Themeasurement takes time because the movement of the probes 26 intocontact with and away from the designated chips and the movement to thenext chip are repeated in each of the light intensity measurement andthe spectrum measurement.

In contrast, according to the present embodiment, the beam splitter 30splits light emitted from the surface-emitting lasers 52. The splitbeams are incident on the photodetector 32 and the spectrometer 38,thereby measuring the light intensity and the spectrum. Because thelight intensity and the spectrum are simultaneously measured, themeasurement time can be shortened compared to the sequential measurementas in the comparative example.

As illustrated in FIG. 2, the plurality of surface-emitting lasers 52are arranged on the wafer 50. After the light intensity and spectrum ofone surface-emitting laser 52 are measured, the light intensity andspectrum of another surface-emitting laser 52 are measured. That is, thelight intensity and the spectrum are simultaneously measured for each ofthe plurality of surface-emitting lasers 52. This considerably shortensthe measurement time compared to the sequential measurement of the lightintensity and spectrum of the plurality of surface-emitting lasers 52 asin the comparative example. The wafer 50 has, for example, 10,000 ormore surface-emitting lasers 52. As one example, a 3 inch wafer 50 has40,000 surface-emitting lasers 52. Because the light intensity and thespectrum are simultaneously measured for many surface-emitting lasers52, for example, 10,000 or more surface-emitting lasers 52, themeasurement time is considerably shortened. As illustrated in FIG. 3, byperforming the measurement after forming the plurality ofsurface-emitting lasers 52 on the wafer 50 and before dicing the wafer50, inspection can be performed within a short period of time during themanufacturing process.

The optical system used for measurement, including the beam splitter 30,the lenses 28, 31, and 36, the photodetector 32, and the spectrometer38, is positioned over one surface-emitting laser 52 designated formeasurement, and the light intensity and the spectrum are measured.Thereafter, the wafer 50 is moved to align another surface-emittinglaser 52 designated for measurement to the optical system. Because thenumber of times of alignment is decreased, the measurement time can beshortened. The effort required for adjustments such as lens focusing isalso halved. Because the number of times the pair of probes 26 are movedinto contact with and away from the surface-emitting lasers 52 is alsodecreased, the measurement time is halved.

Because it is sufficient to add the beam splitter 30 to thephotodetector 32, the power meter 34, and the spectrometer 38, there isno significant cost increase. The beam splitter 30 splits light at theemission wavelength of the surface-emitting lasers 52 in a predeterminedproportion. The control unit 10 can acquire the accurate light intensityand spectrum based on the split proportion and the measurement results.The split proportion need not be 1:1. The spectrometer 38 may bereplaced with, for example, a spectrum analyzer.

When the current/voltage source 20 inputs a current to thesurface-emitting lasers 52, they emit light. When the current is changedand reaches a predetermined level, the light intensity and the spectrumare measured. The current is changed stepwise, for example, in steps of0.2 mA within the range of 0 to 10 mA. The light intensity at eachcurrent can be measured by performing an LIV test for measuring lightintensity while changing the current. The light intensity may bemeasured at all steps of the current or may be measured at certainsteps. For example, when the current reaches a predetermined level Is,the spectrum is measured. If the current Is is set to, for example, 8mA, which is similar to the current through the surface-emitting lasers52 during actual use, a spectrum with high accuracy can be obtained. Thespectrum may be measured at a plurality of currents. The range and stepsize of the current may be changed.

The characteristics of the surface-emitting lasers 52 may change withtemperature change. The thermochuck 24 illustrated in FIG. 1A controlsthe temperature of the wafer 50. According to the embodiment, themeasurement time is halved compared to the comparative example;therefore, the temperature of the wafer 50 changes to a lesser extent.This reduces the change in the characteristics of the surface-emittinglasers 52 with temperature change and thus allows for measurements withhigh accuracy.

Although one embodiment of the present disclosure has been described indetail above, the disclosure is not limited to the specific embodiment.Rather, various changes and modifications can be made within the spiritof the disclosure as set forth in the claims.

What is claimed is:
 1. A surface-emitting laser measuring methodcomprising the steps of: causing at least one surface-emitting laser toemit light; and measuring a light intensity and a spectrum of the atleast one surface-emitting laser by splitting the light emitted from theat least one surface-emitting laser in the step of causing the at leastone surface-emitting laser to emit light and causing one split beam tobe incident on a light-intensity measuring unit while causing anothersplit beam to be incident on a spectrum measuring unit.
 2. Thesurface-emitting laser measuring method according to claim 1, whereinthe at least one surface-emitting laser comprises a plurality ofsurface-emitting lasers arranged on a wafer, the plurality ofsurface-emitting lasers including a first surface-emitting laser and asecond surface-emitting laser, and after the first surface-emittinglaser is subjected to the step of causing light emission and the step ofmeasuring the light intensity and the spectrum, the secondsurface-emitting laser is subjected to the step of causing lightemission and the step of measuring the light intensity and the spectrum.3. The surface-emitting laser measuring method according to claim 2,further comprising the steps of: positioning a splitting unit configuredto split the light over the first surface-emitting laser; and after thestep of measuring the light intensity and the spectrum of the firstsurface-emitting laser, positioning the splitting unit over the secondsurface-emitting laser, wherein the step of measuring the lightintensity and the spectrum comprises measuring the light intensity andthe spectrum by causing one split beam from the splitting unit to beincident on the light-intensity measuring unit while causing anothersplit beam to be incident on the spectrum measuring unit.
 4. Thesurface-emitting laser measuring method according to claim 1, whereinthe step of causing the at least one surface-emitting laser to emitlight comprises changing an amplitude of electrical signals input to theat least one surface-emitting laser to cause the at least onesurface-emitting laser to emit light for each of the electrical signalswith different amplitudes, and the step of measuring the light intensityand the spectrum of the at least one surface-emitting laser comprisesmeasuring the light intensity and the spectrum when the amplitude of theelectrical signals reaches a predetermined level.
 5. A surface-emittinglaser manufacturing method comprising the steps of: forming a pluralityof surface-emitting lasers on a wafer; and subjecting the plurality ofsurface-emitting lasers to the measuring method according to claim
 1. 6.A surface-emitting laser measuring apparatus comprising: alight-emission causing unit configured to cause at least onesurface-emitting laser to emit light; a splitting unit configured tosplit the light emitted from the at least one surface-emitting laser; alight-intensity measuring unit configured to measure a light intensityof the at least one surface-emitting laser by receiving one split beamfrom the splitting unit; and a spectrum measuring unit configured tomeasure a spectrum of the at least one surface-emitting laser byreceiving another split beam.
 7. The surface-emitting laser measuringapparatus according to claim 6, wherein the splitting unit is configuredto split light at an emission wavelength of the at least onesurface-emitting laser in a predetermined proportion.
 8. Thesurface-emitting laser measuring apparatus according to claim 6, whereinthe at least one surface-emitting laser comprises a plurality ofsurface-emitting lasers arranged on a wafer, the surface-emitting lasermeasuring apparatus further comprising a temperature control unitconfigured to control a temperature of the wafer.
 9. A non-transitorycomputer-readable medium having stored therein a program for causing acomputer to execute a process, the process comprising the steps of:causing at least one surface-emitting laser to emit light; and measuringa light intensity and a spectrum of the at least one surface-emittinglaser using the light emitted from the at least one surface-emittinglaser in the step of causing the at least one surface-emitting laser toemit light, the light being split and incident on a light-intensitymeasuring unit and a spectrum measuring unit.